The use of liners in nozzles on gas turbine engines is well known in the art. Such liners are often secured to the inner surfaces of a nozzle to protect those surfaces from the intense heat of the gas turbine exhaust. The liners, which act as thermal barriers to heat transfer between the exhaust gas and the structural components of the nozzle, are critical to preventing life reduction or failure of the structural components.
In the past, such liners have been attached to their respective surfaces by hanger loops 10, of the type shown in FIGS. 1 and 2. These hanger loops 10 are typically welded to a honeycomb panel structure 11, and therefore must be made of a metal that is weldably compatible with the panel 11 metal. Additionally, the hanger loops 10 of the prior art had to be formed from very thin metal to be able to withstand the variety of thermal gradients which occur along the height 12 of the hanger loop during gas turbine operation.
Due to the hanger loops being so thin, the "legs" 13 of each hanger loop 10 must be attached at an angle or which deviates as little as possible from a perpendicular 14 to the panel structure 11 to minimize stress in the hanger legs 13. Consequently, a hanger loop 10 of the prior art had a relatively narrow opening 15, as shown in FIG. 1, making it difficult to insert a retaining pin through a plurality of hanger loops 10 to secure a liner to the panel structure 11. Despite attempts to design a hanger loop 10 which minimizes thermal stresses, a high percentage of the prior art hanger loops 10 fail during use due to stress and thermal fatigue.
What it is needed is a liner hanger which can withstand the thermal gradients to which liner hangers are exposed, and which provides a relatively large opening for easy insertion of the retaining pin.